iOS: You don't have a shortage of great calendar apps to choose from on the iPhone, but if you're looking for something a little different, the Tempo Smart Calendar takes an approach that combines a traditional calendar app with a personal assistant that offers a ton of relevant information.

Tempo works a little like Google Now, where it provides you extra information and context inside the calendar itself. When you create appointments, Tempo Smart Calendar scans your contacts to provide more information about the event, the people who you're meeting with, and where you're meeting. In a lot of cases, Tempo is also smart enough to add in email attachments to meetings when the meeting is mentioned, as well as include a list of contacts who'll attend.

The one issue is that everything is done server side, so you will be storing all your information on their servers instead of on your phone. Also, much like the recently released Mailbox, Tempo currently has a waiting period to sign up for the app. That said, if you're looking for a different kind of calendar app that tries to provide context and information for you before you even need it, Tempo is worth a look.